Portable magnetic-base drill



Dec. '23, 1952 E. w. BUCK PORTABLE MAGNETIC-BASE DRILL 2 SHEETSSHEIET 1 Filed Nov. 6 1951 INVENTOR EugeneWBuck MMA/1.1;.) vx 0 ATTORNEYS Dec. 23, 1952 Filed NOV. 6, 1951 E. W. BUCK PORTABLE MAGNETIC-BASE DRILL 2 SHEETS-SHEET 2 INVENTOR 9 EugeneWBuck B M/ZZ PM ATTORNEYS Patented Dec. 23, 1952 PORTABLE MAGNETIC-BASE DRILL Eugene W. Buck, Campbell, Califi, assignor of one-third to Antonio Cano, Santa Clara, Calif.

Application November 6, 1951, Serial No. 254,993

4 Claims.

This invention relates generally to improve ments in portable electric drills.

In particular the invention is directed to, and it is a major object to provide, a portable electric drill which includes a novel electro-magnetic base or foot arrangement operative to releasably secure the drill to metal work without the necessity of manually holding the drill in place or employing a mechanical clamp for the purpose.

Another important object of the invention is to provide a portable electric drill, as above,

wherein the electro-magnetic base or foot arrangement includes a pair of electro-magnetic feet mounted and disposed in a manner to afford positive, well stabilized attachment to metallic work when the drill is in use; the foot assembly being positioned so as to permit drilling in the corner of a work piece or close to an end or edge thereof.

An additional object of the invention is to provide an electro-magnetic base or foot assembly, as above, in combination in a portable electric drill which includes an upstanding frame structure adapted for radial, and lateral swinging, adjustment of the drill. The foot assembly is operative to facilitate the making of the desired adjustment, in that one magnetic foot is placed in operation to initially position the frame structure, and the other magnetic foot is placed in operation after the desired adjustment to then hold the drill in a stabilized position.

A further object of the invention is to provide a portable drill, of the type described, wherein each electro-magnetic foot is of novel structure, being capable of exerting a strong holding force on metal work on which the device is to be used.

It is also an object of the invention to provide a portable magnetic-base drill which is designed for ease and economy of manufacture, and convenience of use.

Still an additional object of the invention is to provide a practical and reliable portable magnetic-base drill, and one which will be exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings:

Fig. 1 is a side elevation of the drill as in use.

Fig. 2 is a fragmentary sectional plan on line 22 of Fig. 1.

Fig. 3 is a fragmentary sectional plan on line 3-3 of Fig. 1.

Fig. 4 is an enlarged fragmentary elevation, mainly in section, showing the lower portion of the secondary post as connected with the secondary electro-magnetic supporting foot.

Fig. 5 is an enlarged fragmentary sectional plan on line 55 of Fig. 1.

Referring now more particularly to the characters of reference on the drawings, the portable magnetic-base drill comprises a main post, indicated generally at I, such post being fitted, at its lower end, with a horizontal, circular attachment plate 2 which rests on and is secured by cap screws to a primary, electro-magnetic supporting foot, indicated generally at 3, and which is likewise circular in plan.

Directly ahead of the main post I there is a secondary post 4 similarly fitted at its lower end with a secondary, electro-magnetic supporting foot 5, also circular in plan.

The electro-magnetic supporting foot 5 is attached to the secondary post 4 as follows:

The secondary post 4 is tubular, terminatin at its lower end some distance above the corresponding end of the main post I. A plunger 6 is slidably disposed in the post 4 and is threadingly engaged, as at 1, on the upper end of a stem 8 which projects downwardly through a reduceddiameter bore 9 in the lower end of said post 4; the stem 8 thence projecting downwardly and being coupled by a ball and socket unit Ill to the secondary, electro-magnetic supporting foot 5 centrally thereof.

A compression spring S surrounds the stem 8 between the plunger 6 and the lower end of the tubular secondary post 4;. such compression spring S being under load and, when the electromagnetic supporting foot 5 is deenergized, acting to lift such foot clear of the horizontal plane of the bottom of the primary electro-magnetic supporting foot 3; i. e. to the position shown in dotted lines in Fig. 1.

The primary and secondary electro-magnetic supporting feet 3 and 5 are of substantially identical construction, and therefore the following description will suffice for both:

Each of said feet comprises a horizontal, circular body I l of iron, having an annular channel I2 machined thereinto from the bottom whereby to form a central core l3.

A11 annular co l l s disposed in the channel l2, being supported from below by a retention,

ring [5 secured in the annular channel I 2 by set screws l6.

Each of the coils I4 is connected to a direct current supply circuit, indicated diagrammatically at IT, and each circuit has a switch l8 u therein. With this circuit arrangement it is possible to energize the primary and secondary electro-magnetic supporting feet 3 and 5 selectively and independently.

At the upper end thereof the main post I turnably supports a horizontal axis, split clamping sleeve I9, such sleeve including a depending spindle 29 which runs in a vertical axis split clamping sleeve 2| included in said post at the upper end. The clamping sleeve 2! includes a clamping screw 22 whereby the spindle l2 may be locked up in the post I so as to prevent rotation of the clamping sleeve I9 about its vertical axis.

A tubular radial arm 23 extends horizontally through the clamping sleeve 19, being guided for radial adjustment by means of upper and lower longitudinal keys 24. The clamping sleeve I9 includes a screw 25 by means of which the sleeve I9 is normally clamped about the arm 23.

The secondary post i is fixed at its upper end to the forward end of the radial arm 23.

Ahead of the secondary post 4 there is a vertically disposed guideway 26 fixed in connection with the forward end of said radial arm 23, and such guideway 26 has a vertical slide plate 21 running therein; there being a vertical rack 23 on the back side of said slide plate 21.

The rack 23 has a pinion 29 in mesh therewith directly above the forward end of the radial arm 23; such pinion being carried on a pin ion shaft 39 in a fixed housing 3!. A spider handle 32 is secured to one outer end of the pinion shaft 39 laterally of the radial arm 23, thus being accessible to rotate said pinion shaft 39 and the pinion 29 therein for the purpose of running the rack 23 and the slide plate 2? up or down in the guideway 23.

A hand-type electric drill, indicated generally at 33, is disposed in an upstanding position in front of the guideway 23 and is attached to the slide plate 21 by upper and lower attachment blocks, indicated at 34 and 35.

The upper attachment block 34 includes a forwardly projecting bracket arm 36 which matchingly engages the top of the drill grip 3?, being connected to the latter by a clamp 38. The lower attachment block 35 has suitable connection with the body of the drill 33, as shown.

With the drill 33 mounted as described the chuck 39 projects downwardly for the reception of a twist drill 49.

The above described portable magnetic-base drill is used in the following manner:

The primary electro-magnetic supporting foot 3 is first disposed on the metallic work 4| and energized, whereby said foot is magnetically clamped to such work. Thereafter, the radial arm 23 is adjusted, by proper manipulation with the clamping sleeves l and 2| released, to desired direction and extent of projection. When this adjustment is completed, the sleeves I9 and 2! are reclamped; the portable electric drill 3 being clear of the work M during such adjustment of the radial arm 23.

After the radial arm 23 is adjusted to dispose the twist drill 40 directly over the work point, the secondary electro-magnetic supporting foot is energized, whereupon it snaps down against the load of the compression spring 3 and clamps itself on the work 4!; the ball and socket unit permitting the foot 5 to aline itself with the foot 3 in effective matching engagement with said work.

Thereafter, with the electric drill 3 in opera- '4 tion, the spider handle 32 is rotated in the proper direction to cause the rack 28 and vertical slide plate 21 to move downwardly, whereby to urge the twist drill 40 into the work 4 I.

While the primary electro-magnetic supportin foot 3 provides the main support for the tool, the secondary electro-magnetic supporting foot 5 stabilizes the tool, resists the torque of the drill, and opposes the upward thrust which such drill produces when it is run into the work.

Thus, with the described electro-magnetic foot assembly the drill is positively and effectively maintained clamped to the work during the drilling operation, yet without the necessity of employing a mechanical, work gripping clamp.

Another feature of importance is that both of the electro-magnetic feet 3 and 5 are in alinement in the same direction away from the twist drill 40, the result being that the drill can be used in close quarters, asf0r examp1eclose to the edge of a plate, at a corner thereof, or at the end of a beam.

From the foregoing description it will be readily seen that there has been produced such a device as substantially fulfills the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired:

1. In a portable magnetic-base drill, an upstanding main supporting post, an electro-magnetic foot on the lower end of the post, a radial arm projecting from the post at its upper end and horizontally ad ustable relative thereto, a vertical drill unit supported from the outer end of the arm, a secondary post depending from the arm adjacent its outer end, and an electro-magnetic foot on the lower end of said secondary post.

2. A device as in claim 1, with means to separately control the energizing of the feet.

3. A device as in claim 1, with means between the secondary post and said last named foot to hold the latter when de-energized in a raised position relative to the first named foot.

4. A device, as in claim 3, in which said secondary post is tubular, and said last named means includes a plunger therein, a stem secured to the plunger and projecting downward therefrom, a connection between the lower end of the stem and said second foot, and a spring in the tubular post holding the plunger upward in an initial position with said second foot raised relative to said one foot. EUGENE W BUCK REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

